Blockchain Java Backend Developer

Job Location and Compensation

Jersey City, NJ

Salary Range: $100,000-$130,000 per year

4-6 years of experience

Design and develop Java-based backend services that interact with blockchain networks and nodes (public or permissioned).

Build and scale microservices-based architecture supporting blockchain transaction workflows, event processing, and off‑chain components.

• Transaction orchestration
• Smart contract invocation

Implement scalable APIs (REST/gRPC) for blockchain-enabled products and integrations.

Optimize performance for high throughput and low latency, including transaction throughput handling, batching, retries, idempotency, and rate limiting.

Ensure secure integration with blockchain networks.

Implement observability and reliability standards.

Work with Dev Ops/SRE teams to support production deployments, incident triage, and capacity planning.

Contribute to architecture decisions including event‑driven architecture (Kafka/Rabbit

MQ), caching strategies, database selection, and deployment topologies.

Core Backend Skills

• Strong proficiency in Java (8+) and frameworks such as Spring Boot / Spring Cloud.
• Experience building distributed systems and microservices architectures at scale.
• Strong knowledge of concurrency, multithreading, asynchronous programming, API design (REST/gRPC), security (OAuth2/JWT), and integration patterns.
• Solid understanding of data stores including caching (Redis) and search (Elasticsearch) considered a plus.
• Hands‑on experience with message streaming/queues.

Blockchain Skills (Must‑Have)

• Strong understanding of blockchain fundamentals: transactions, blocks, confirmations/finality, consensus, gas/fees, wallets, keys.
• Experience integrating backend services with blockchain networks/nodes, including Ethereum-compatible networks (Ethereum/Polygon/BSC) using Web3j, ethers‑style approaches, and/or permissioned chains (Hyperledger Fabric, Corda, Quorum).
• Node connectivity, RPC management, event indexing, chain reorg handling, retry strategies.

Container & Cloud

• Docker and Kubernetes for containerized microservices deployments.
• Cloud experience (Azure/AWS/GCP) is a plus.

Security Practices

• Secrets management (Vault/KMS), TLS, RBAC, network security.

Bachelor of Computer Science.